Ccna routing and Switching Complete Study Guide

Connecting to a Cisco IOS Device

We connect to a Cisco device to configure it, verify its configuration, and check statistics, 

and although there are different approaches to this, the first place you would usually con-

nect to is the console port. The console port is usually an RJ45, 8-pin modular connection 

located at the back of the device, and there may or may not be a password set on it by 

default.

Look back into Chapter 2, “Ethernet Networking and Data Encapsulation,” 

to review how to configure a PC and enable it to connect to a router con-

sole port.

You can also connect to a Cisco router through an auxiliary port, which is really the 

same thing as a console port, so it follows that you can use it as one. The main difference 

with an auxiliary port is that it also allows you to configure modem commands so that a 

modem can be connected to the router. This is a cool feature because it lets you dial up a 

remote router and attach to the auxiliary port if the router is down and you need to config-

ure it remotely, out-of-band. One of the differences between Cisco routers and switches is 

that switches do not have an auxiliary port.

The third way to connect to a Cisco device is in-band, through the program Telnet or 

Secure Shell (SSH). In-band means configuring the device via the network, the opposite of 

out-of-band. We covered Telnet and SSH in Chapter 3, “Introduction to TCP/IP,” and in 

this chapter, I’ll show you how to configure access to both of these protocols on a Cisco 

device.

Figure 6.1 shows an illustration of a Cisco 2960 switch. Really focus in on all the differ-

ent kinds of interfaces and connections! On the right side is the 10/100/1000 uplink. You 

can use either the UTP port or the fiber port, but not both at the same time.

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Chapter 6 

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  Cisco’s Internetworking Operating System (IOS)

f I g u r e   6 .1     A Cisco 2960 switch

The 3560 switch I’ll be using in this book looks a lot like the 2960, but it can perform 

layer 3 switching, unlike the 2960, which is limited to only layer 2 functions.

I also want to take a moment and tell you about the 2800 series router because that’s 

the router series I’ll be using in this book. This router is known as an Integrated Services 

Router (ISR) and Cisco has updated it to the 2900 series, but I still have plenty of 2800 

series routers in my production networks. Figure 6.2 shows a new 1900 series router. The 

new ISR series of routers are nice; they are so named because many services, like secu-

rity, are built into them. The ISR series router is a modular device, much faster and a lot 

sleeker than the older 2600 series routers, and it’s elegantly designed to support a broad 

new range of interface options. The new ISR series router can offer multiple serial inter-

faces, which can be used for connecting a T1 using a serial V.35 WAN connection. And 

multiple Fast Ethernet or Gigabit Ethernet ports can be used on the router, depending on 

the model. This router also has one console via an RJ45 connector and another through 

the USB port. There is also an auxiliary connection to allow a console connection via a 

remote modem.

f I g u r e   6 . 2     A new Cisco 1900 router

You need to keep in mind that for the most part, you get some serious bang for your 

buck with the 2800/2900—unless you start adding a bunch of interfaces to it. You’ve 

got to pony up for each one of those little beauties, so this can really start to add up 

and fast!

A couple of other series of routers that will set you back a lot less than the 2800 series 

are the 1800/1900s, so look into these routers if you want a less-expensive alternative to 

the 2800/2900 but still want to run the same IOS.

So even though I’m going to be using mostly 2800 series routers and 2960/3560 switches 

throughout this book to demonstrate examples of IOS configurations, I want to point out 

that the particular router model you use to practice for the Cisco exam isn’t really impor-

tant. The switch types are, though—you definitely need a couple 2960 switches as well as a 

3560 switch if you want to measure up to the exam objectives!

You can find more information about all Cisco routers at 

www.cisco.com/

en/US/products/hw/routers/index.html

.

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Command-Line Interface (CLI)